Esophageal ulceration due to indomethacin

Group I secreted PLA2 in the maintenance of human lower esophageal sphincter tone

BACKGROUND & AIMS

In cat spontaneous lower esophageal sphincter (LES), tone is maintained by the activity of group I secreted phospholipase A2 (sPLA2-I) that produces arachidonic acid. Arachidonic acid metabolites activate G proteins linked to phospholipases, producing second messengers and activation of a protein kinase C-dependent pathway to maintain tone. We examined the role of sPLA2-I in the maintenance of tone in human LES samples obtained from organ donors.

METHODS

In vitro LES tone and sPLA2-I-induced contraction of enzymatically isolated LES smooth muscle cells were measured in the absence or presence of inhibitors. Cell permeabilization by saponin allowed use of G-protein antibodies.

RESULTS

In vitro LES tone was reduced by inhibitors of sPLA2-I, by indomethacin, by the phosphatidylcholine-specific phospholipase C inhibitor D609, and by the protein kinase C inhibitor chelerythrine. sPLA2-I-induced contraction of isolated LES smooth muscle cells was reduced by indomethacin, pertussis toxin, Gi3 antibodies, D609, and by chelerythrine.

CONCLUSIONS

Human LES tone is maintained by the activity of sPLA2-I that produces arachidonic acid and metabolites and activation of Gi3-linked receptors and of phosphatidylcholine-specific phospholipase C, resulting in production of diacylglycerol, activation of PKC, and maintenance of tone through a protein kinase C-dependent contractile pathway.

Esophageal manifestations of rheumatic disorders

This study was performed to review information on functional and anatomic esophageal manifestations in patients with rheumatic disorders and to outline their pathogenesis, diagnosis, and treatment in light of the current medical, endoscopic, and surgical advances. A MEDLINE search of English-language articles published between 1985 and 1995, reviews of the bibliographies of textbooks, and a manual search of the reference lists of relevant articles formed the data sources, all combined with our own clinical experience. Primary research and review articles addressing the pathogenesis, diagnosis, treatment, prognosis, and complications of esophageal disease occurring in a rheumatic context were selected, with emphasis on recently developed medical, endoscopic, and surgical methods for diagnosis and management. Study design and quality were assessed, with particular attention paid to methods and aims. Relevant data on frequency, clinical presentation, and relationship to underlying rheumatic disorder, prognosis, and clinical management were analyzed. Esophageal manifestations are common in patients with rheumatic diseases and range in nature and severity from functional myopathic or neuropathic esophageal dysmotility to extrinsic lumenal compression and esophageal mucosal damage from gastroesophageal acid reflux or opportunistic infection. The primary symptoms of heartburn, dysphagia, odynophagia, chest pain, and bleeding may be directly related to the underlying rheumatic disease or may be the unwanted effects of therapy with nonsteroidal antiinflammatory drugs, immunosuppressants, or disease-modifying agents. Easily over-looked in the context of a multisystemic disease, these esophageal symptoms may be amenable to simple treatments, but frequently require a thorough assessment by modern, sophisticated diagnostic tools. In many instances, functional and structural involvement of the esophagus in patients with rheumatic disorders requires a high index of suspicion for an early diagnosis, correct assessment, intensive surveillance, and aggressive therapy to avoid end-organ damage and decline in quality of life. Significant recent advances in the understanding of esophageal pathophysiology, the development of diagnostic techniques, progress in diagnostic and therapeutic endoscopy, and minimally invasive surgery allow early detection and effective long-term therapy for esophageal dysfunction associated with rheumatic diseases.

Pill-induced esophageal strictures: clinical features and risk factors for development

Clinical data from five subjects with pill-induced esophageal strictures and from the English-language literature on pill-induced esophageal damage were reviewed to determine risk factors for stricture development and to characterize this complication. Including our five cases, 195 patients with pill-induced damage and 39 patients with pill-induced strictures have been reported to date. Seventy-eight percent of the strictures were located in the proximal or mid-esophagus. Potassium chloride or quinidine preparations were incriminated in 60% of cases and were more likely to produce stricture than other medications commonly associated with esophageal damage (e.g., tetracycline). Older age, male gender, left atrial enlargement, ingestion of sustained-release formulations, and prior esophageal structural abnormality were all more commonly present in the subset with strictures (p less than 0.05 for each), even after appropriately controlling for medication. A logistic regression analysis revealed that older age and ingestion of sustained-release formulations were the most significant independent factors associated with stricture development (p less than 0.0001 for each). These findings indicate that stricture formation from pill-induced esophageal damage is dependent upon host-related factors as well as the caustic nature of the pill.

Medication-induced oesophageal injury. Survey of the literature

This is a review of the 127 cases of drug-induced oesophagitis reported in the English language literature since 1970. The most common symptoms reported were retrosternal pain, odynophagia, and dysphagia. Most cases were self-limited and symptoms resolved in 7 to 10 days with symptomatic therapy. Occasionally, severe odynophagia or dysphagia necessitated hospitalisation. Emepronium bromide, tetracycline and its derivatives, potassium chloride, and quinidine account for 89% of the reported cases of medication-induced oesophageal injury. 14 other medications have been reported to injure the oesophagus. Serious sequelae, including death, have been linked to potassium-induced oesophageal injury. With other medications, however, serious complications were rare. The diagnostic study of choice is endoscopy; an air-contrast barium swallow may also detect the often subtle mucosal abnormalities produced by medication injury. However, the diagnosis does not require confirmation by radiographical or endoscopic means in all cases, and the history alone may be sufficient to make the diagnosis in uncomplicated cases. Medication-induced oesophageal injury is preventable if pills are taken with an adequate amount of fluid and if the practice of taking medications immediately before bedtime is avoided.

Adverse reactions to nonsteroidal anti-inflammatory drugs. Diclofenac compared with other nonsteroidal anti-inflammatory drugs

The most common adverse effects of nonsteroidal anti-inflammatory drugs are gastritis, peptic ulceration, and depression of renal function, all of which result primarily from prostaglandin inhibition. The types of side effects observed with diclofenac are similar to those of other nonsteroidal anti-inflammatory drugs and are unavoidable given that the drugs are prostaglandin inhibitors. However, the incidences of such side effects may be lower with diclofenac than with some of the other nonsteroidal anti-inflammatory drugs. Worldwide experience with diclofenac exceeds 7.6 million patient-years, which should provide estimates of the frequency of very rare adverse reactions. The latter include blood dyscrasias, erythema multiforme, hepatitis, and others, such as aseptic meningitis, anaphylaxis, and urticaria. Moreover, some nonsteroidal anti-inflammatory drugs appear to have unique side-effect profiles. Examples include a higher incidence of ulceration and erythema multiforme with piroxicam, and acute pancreatitis, in rare instances, with sulindac. From a careful survey of the world's accumulated literature and reports to CIBA-GEIGY, diclofenac does not appear to have any unusual adverse reactions.